Semiconductor devices using mos transistors with nonuniform gate electrode structures and methods of fabricating the same

Abstract

A semiconductor device includes a substrate and first and second gate electrodes on the substrate. The first gate electrode includes a first gate insulation film having a bottom portion on the substrate and sidewall portions extending from the bottom portion and away from the substrate defining a first trench having a first width and a first functional film filling the first trench. The second gate electrode includes a second gate insulation film having a bottom portion on the substrate and sidewall portions extending from the bottom portion defining a second trench having a second width different from the first width, a second functional film conforming to the second gate insulation film in the second trench and defining a third trench, and a metal region in the third trench. The first width may be less than the second width.

1 . A semiconductor device comprising:
 a substrate;   a first gate electrode comprising:
 a first gate insulation film having a bottom portion on the substrate and sidewall portions extending from the bottom portion and away from the substrate defining a first trench having a first width; and 
 a first functional film filling the first trench; and 
   a second gate electrode comprising:
 a second gate insulation film having a bottom portion on the substrate and sidewall portions extending from the bottom portion defining a second trench having a second width different from the first width; 
 a second functional film conforming to the second gate insulation film in the second trench and defining a third trench; and 
 a metal region in the third trench. 
   
     
     
         2 . The semiconductor device of  claim 1 , wherein the first width is less than the second width. 
     
     
         3 . The semiconductor device of  claim 1 :
 wherein the first functional film comprises a first work function control film conforming to the sidewall and bottom portions of the first gate insulation layer in the first trench and a first barrier film on the first work function control film; and   wherein the second functional film comprises a second work function control film and a second barrier film on the second work function control film.   
     
     
         4 . The semiconductor device of  claim 3 :
 wherein the first functional film further comprises a third work function control film; and   wherein the second functional film further comprises a fourth work function control film.   
     
     
         5 . The semiconductor device of  claim 4 , wherein the first and second work function control films are N type and wherein the third and fourth work function control films are P type. 
     
     
         6 . The semiconductor device of  claim 3 , wherein the first barrier film comprises titanium nitride (TiN). 
     
     
         7 . The semiconductor device of  claim 6 , wherein the metal region comprises tungsten (W). 
     
     
         8 . The semiconductor device of  claim 1 , further comprising a first fin and a second fin on the substrate, wherein the respective ones of the first and second gate electrodes are disposed on respective ones of the first and second fins. 
     
     
         9 . The semiconductor device of  claim 1 , wherein the first gate electrode and the second gate electrode have the same height. 
     
     
         10 . The semiconductor device of  claim 1 , wherein the first and second gate electrodes are disposed in cell array and peripheral circuit regions, respectively. 
     
     
         11 .- 16 . (canceled) 
     
     
         17 . A semiconductor device comprising:
 a substrate;   a first fin transistor disposed on the substrate and comprising:
 a first semiconductor fin protruding from the substrate; 
 a first gate electrode crossing the first semiconductor fin and comprising:
 a first gate insulation film having a bottom portion disposed on the substrate and conforming to the first semiconductor fin, and sidewall portions extending from the bottom portion and away from the substrate; 
 at least one first work function control film conforming to the bottom and sidewall portions of the first gate insulation film; and 
 a first barrier film filling a first trench defined by the at least one first work function control film; and 
 
 first source/drain regions on opposite sides of the first gate electrode; 
   a second fin transistor disposed on the substrate and comprising:
 a second semiconductor fin extending from the substrate; 
 a second gate electrode crossing the second semiconductor fin and comprising:
 a second gate insulation film having a bottom portion disposed on the substrate and conforming to the second semiconductor fin, and sidewall portions extending from the bottom portion and away from the substrate; 
 at least one second work function control film conforming to the bottom and sidewall portions of the first gate insulation film; 
 a second barrier film conforming to the at least one second work function control film; and 
 a metal region filling a trench defined by the at least one second work function control film; and 
 
 second source/drain regions on opposite sides of the second gate electrode. 
   
     
     
         18 . The semiconductor device of  claim 17 , wherein the second gate electrode is wider than the first gate electrode. 
     
     
         19 . The semiconductor device of  claim 17 , wherein the at least one work first function control film comprises a plurality of first work function control film and wherein the at least one second work function control film comprises a plurality of second work function control films. 
     
     
         20 . The semiconductor device of  claim 17 , wherein the first fin transistor and the second fin transistor are disposed in a cell array region and a peripheral circuit region, respectively.